The danger of disease transmission among personnel who come into contact with contaminated materials or diseased persons, and especially the danger to those exposed to blood or other body fluids, has motivated the development of various devices and methods to prevent inadvertent infection.
It is especially desirable to provide means for protection from accidental pricking or puncture with contaminated intravenous needles. The problem is particularly acute in the collection and handling of blood or other body fluids when needles are used to pierce a vein and/or to transfer such fluids to various receptacles for testing and the like. Such means should be inexpensive, easy to use and provide for easy manipulation of the needle into and out of operative shielded and unshielded relationship.
In response to this problem, various shield devices have been developed to limit the exposure of personnel to the sharp point of the needle. Examples of prior art shields are shown in U.S. Pat. Nos. 4,659,330 and 4,737 114. Each of these patents describes tubular sheaths which encase the needle when the needle is not in use. Other needle protecting devices are disclosed in U.S. Pat. Nos. 2,854,976, 2,990,059, 3,709,223, 3,901,226, 3,973,565, 4,007,740 and 4,170,993. These patents do not suggest a shield envelope into which the needle may be withdrawn as it is removed from the venipuncture site.